The council believes the programme, which will start this year and run until 2014, will be partly financially offset by savings resulting from more efficient work practices in the refurbished offices.
A report by strategic director of the Manchester Improvement Programme Elaine Bowker and city treasurer Richard Paver said: “The refurbishment programme has cultural and behavioural change at its heart, which will ensure that when the town hall complex is reopened, it will be for the benefit of all of the citizens of Manchester.”
A new customer service centre will be created in the town hall extension building, while an increase in office space will enable the council to vacate premises elsewhere in the city.
It was decided to renovate the town hall extension in one go, rather than on a floor-by-floor basis to cut construction costs. To enable the work to proceed, it is expected staff will temporarily move to new offices at the Spinningfields city centre development.